In the introduction to this nearly 700-page collection of the letters of Hunter S. Thompson, the novelist William J. Kennedy provides a useful definition of the "gonzo journalism" that made Thompson famous. "It was not lunacy defined," Kennedy writes, "but lunacy imagined: in short, a novel." Unfortunately, in these pages Thompson most often cnfines himself to the mundane facts of his everyday life between 1955 (when he was 17 years old) and 1967 (following the publication of Hell's Angels), and the results are generally underwhelming. Occasionally we see flashes of humor or intelligence, but for vast stretches we are subjected to observations like these: "I have paid my rent for one...